Flap gate



1943- c. 5. BROWN 2,328,419

FLAP-GATE Filed July 1, 1941 2 Sheets-Sheet l gnoem 1943 c. 5. BROWN2,328,419

FLAP-GATE Filed July 1, 1941 2 Sheets-Sheet 2 H6 5 @& a/mwzflmwnPatented Aug. 31, 1943 FLAP GATE Chalmers S.

Brown, Lima, Ohio, assignor to Brown and Brown, Incorporated, Lima,Ohio, a

corporation of Ohio Application July, 1, 1941, Serial No. 400,678 3Claims. (01. 251 123) My invention has for its object to provide aflap-gate for controlling discharge of water or, other liquids throughpipes. The invention is particularly advantageous when usedforcontrolling the flow of liquids in pipes to provide for the dischargeof liquids where there is a variation in the liquid level that affectsthe outflow from the discharge pipes. The invention thus provides aneflicient flap-gate or back water gate to prevent the influx of waterinto the discharge pipe.

'By reason of the common use of corrugated sheet metal pipes, the gateis provided with a rigid frame for pivotally and swingedly supportingthe movable part of the gate and forming a seat for the gate. Also adurable means is provided for securely connecting the supporting frameto the thin wall of the sheet metal pipe that is operable to prevent theconstant unusual working of the gate from tearing the frame from the endof the pipe. Thus, the frame of the gate is secured to the pipe througha lead cushion that eliminates imtial tearing of the pipe metal.

The invention is of particular value when used as a tide water gatewhere, during the rise of the tide, there is considerable deposition ofsand at the outlet of the discharge pipe. The gate is opened and closedby the differential of the head pressures of the tide Water on theoutside of the gate and the liquid within the pipe, and also by the tiltof the gate produced by the sand, as modified by the supporting means ofthe movable part of the gate, and also by the configuration of thecontacting lower edge portions of the parts of the gate which enablesthe gate to slide relative to its seat as the gate is pivoted and raisedto an open position or is lowered to a closed position.

The invention may be contained in structures of difierent forms, and toillustrate a practical application of the invention, a flap gate isshown in the drawings that may be greatly varied in its details withinthe scope of the clams hereinafter appended.

Figure 1 of the drawings illustrates a perspective of the flap-gate.Figure 2 is a view of a section of a clamp for securing the gate to acorrugated sheet metal pipe. Figure 3 is a view of a section of thegate. Figure 4 illustrates a tide gate, somewhat open or partiallyclosed, where the sand is not all removed by the outward current of theliquid from the pipe. Figure 5 illustrates a section of coasting edgesof the seat and movable valve member of the gate.

The discharge pipe I conveys the liquid to be discharged to a point thatmay be in the region low the uppermost part of the edge of the gate andto the edge of the gate, and the links are connected to the frame 1 atpoints well above the valve seat 8 of the frame to produce a freemovement, within a limited range, of the flap valve relative to thelinks, such as is shown in Figure 4. The outward movement of the valverelative to the links may be adjustably limited by the screws l3.

The frame 1 may be connected to the end of the pipe I by means of theradially extending lugs II and the clamps 12. The rear edge of the frame1 is formed frustumal as at M to substantially correspond with the endflare of the corrugated pipe formed by cutting the pipe along the ridgeof one of its corrugations. The lugs II have ridges I5 that havesemi-circular surfaces and the clamps I?! have recesses ll also havingcircular surfaces that fit the ridges l5, and, therefore, the clampspivot on the ridges when the other end I8 is in engaging relation withthe flared edge I 9 of the pipe I. Preferably, the end l8 of the clampis provided with a lead strip 20 having edge parts turned up and aboutthe corners of the end [8 of each clamp l2 to form a yielding cushionfor engaging the surface of the end of the thin sheet metal wall of thepipe I and clamp it to the surface [4 of the frame I by the bolt 2|.

The centers of the links 5 ar substantially in the vertical plane of thecenter of gravity of the movable part of the gate, and thus the tidegate operates by the differential head of the liquids within the pipeand exterior to the gate, and, by reason of the support of the valvemember 4 by the links 5, it operates quite in accordance with therelative height of the centers of pressure of the liquid within andWithout the gate. Thus, on the drop of the level of the liquid outsideof the gate, there is a tendency of the gate to open at the top of thepipe. When this occurs, it allows the liquid to move between the loweredge portions of the valve and its seat. This is particularly the casewhere sand is deposited exterior to the gate during the high tide andafter the closure of the gate. The sand engages the lower edge of thegate and the center of pressure of the liquid within the gate causes Thevalve member 4 is preferably cir-. oular and is connected to the linksat points bethe upward edge of the gate 4 to tilt outward by the freeswing of the lower ends of the links 5. The downward wash of the waterfrom the pip I from between the edges of the gate and the frame, andparticularly the bottom edge portions thereof, will, as indicated inFigure l, wash a large part of the deposited sand away from the loweredge. of the gate and free the gate for opening at thebottom of the pipeas well" as at the top, or, if a large amount of sand is deposited, itmay hold the gate in its tilted position until the gate is closed by thechange from outward flow to inward flow.

In the outward flow during the engagement of the gate by the sand, theheadoi the water with.- in the pipe is higher than that of' the wateroutside of the gate, and also, the tilt of the gate by engagement of thesand and the pressure in the pipe causes the link to swing upward andoutward and the lower edge of the gate to rise and swing inward aslimited by the edgesof: theLfi'ap and itsseatand open' thevend of thepipe; Tozaidt in such movement, the lower semi-circular edgev portions22 and.v 2'4'-ofthe flap and. th seat are rounded as indicated in Figure5. This move- .ment also opens the gate-at thelower sideoi the wellabove the top of the gate member and the otherpair of ends pivotallyconnected to the-edgeoft'hegatem'emb'er'well below the top of the gatemember for pivota'lly' andswinging-ly supporting thega-te memberto-permit free inward and outward movement of the lower edge of the gatemember with respect to the" valve-seat; thelower semi-circular inner'edgeof the valve seat and the lower' semi-circular outer edge ofthevalve face formed convexedl'y curved to produce rela ti'vely freesliding movement of one edge on the other up'on rai s-ing'of'the movablegatemember byoutward swinging of the links caused by the location of thecenter of pressure of the liquid of the interior surface of the gatemember above that of the center of pressure of the liquid on theexteri'or surface of the gate member.

2. In a flap-gate for controlling the flow of liquid through a dischargepipe into tide water having depositable sand, a movable circular atemember having a valve face; a circular gate supporting frame forconnection to the end of the discharge pipe and having a valve seatcoacting with the valve face for closing the said valve seat; a pair oflinks having one pair of ends pivotally connected to the frame at apoint well above thetop off the-gate member and the other pairofend'spivotally connected to the gate for pivotally and swinginglysupporting the gate member; and the lower semi-circular inner edge ofthev valve seat and the lower semi-circular outer edge of the valve faceformed convexedly curved to produce( relatively free.- sli'dingmovemBIlt of' one round'edl edge: on the other upon: raising of themovable gate-.member by outwards swinging of? the links and. opening:of: the valve seat at the lower part Ofl the frame caused bythe:location of the; center: of pressure: of. the

liquid. on the interiorsurfaceiof theigatemember:

above that of the? center of pressure of th liquid.

and sandon the; exterior; surface of: the gate: member to removethesand: which may lodge. onv the valve face or the valve seat.

3.111 a flap-gate for controlling the flow of liquid; through; a sheet:metal discharge pipe into.

tide: water having depositable' sand; a movablecircul'ar. gate member;having. a valve face; a:

circular gate seat frame;pivotally-supporting said strips? located; onthe ends of the clamps; remote from the" recesses; and boltsfor forcing:the lead strips against-the pipe and: the pipe against the frustumalisurface of: the seat frameas therclainipsi are pivotally moved about.the semi-cylindrical surfaces of; the ridges" of the lugs upon' tightening the bolts; for securing the seat framev to thepipe;

CHALMERS S. BROWN.

